One of the more preferred methods of controlling weeds in crops involves the post-emergent control of weeds wherein herbicide(s) are applied after the crop in question has emerged from the soil. Post-emergent control is desirable as it requires the application of herbicide only where an infestation of weeds is present. In contrast, pre-emergent control requires the application of herbicide early in the growing season before most weeds have germinated, with the result that such chemicals must be employed throughout a field even if they would ultimately not be needed.
Fluthiacet-methyl, or methyl [[2-chloro-4-fluoro-5-[(tetrahydro-3-oxo-1H,3H-[1,3,4]thiadiazolo[3,4-a]pyridazin-1-ylidene)amino]phenyl]thio]acetate, is an effective post-emergent herbicide for a number of weeds, particularly broadleaf weeds.
p-Hydroxyphenylpyruvate dioxygenase (HPPD) is an enzyme found in both plants and animals, which catalyzes the catabolism of the amino acids phenylalanine and tyrosine. Inhibition of this enzyme has profound effects on plants, affecting the formation of homogentisic acid which is a key precursor for the biosynthesis of both tocopherols (vitamin E) and plastoquinone, a critical co-factor in the formation of carotenoids, which protect chlorophyll in plants from being destroyed by sunlight.